A depth camera has a certain resolution as an ordinary camera does. However, for each pixel of a depth camera, the distance from an object corresponding to the pixel to the camera is stored. Such a distance can be referred to as depth. As such, a depth camera outputs a depth map, and the value of each pixel on the depth map represents the distance from an object corresponding to this pixel to the camera.
A depth camera using a ToF (Time of Flight) sensor outputs a depth map through ToF technology, wherein ToF technology measures the distance between an object that reflects an optical signal and the transmitting and receiving ends by transmitting and receiving a modulated optical signal and analyzing the time difference between the transmitted and received optical signals. A ToF sensor is an element receiving and analyzing optical signals in the practical application of the ToF technology, which cooperates with an element emitting modulated optical signals to achieve depth measurement. Generally, a depth map can be obtained through some mathematical transformation of the output of the ToF sensor.
At present, a depth camera with a single ToF sensor is typically used in the industry. Generally, a depth camera with a single ToF sensor has a smaller field of view within which the depth can be measured, and thus may fail to meet the needs of some applications that require a depth map with a large field of view. In order to meet the needs of applications requiring a depth map with a large field of view, it is often necessary to use a plurality of single-ToF-sensor depth cameras in the same scene. In this case, however, there is a problem that the depth cameras interfere with each other due to asynchronization of modulation and demodulation.